Self and wilhelm grillo



(Spec1mens.)

M. SOHBOEDER. EXTRAGTING FATS AND OILS.

No. 433,152. Patented July 29, 1890.

WITNESSES. w W y takes place even in this case.

UNITED STATES PATENT OF ICE.

MAX SCHROEDER, ()F NEUMUIlL-HAMBORN, GERMANY, ASSIGNOR TO HIM- SELF ANDVILHELM GRILLO, OF SAME PLACE.

EXTRACTING FATS AND O |LS.

SPECIFICATION forming part of Letters Patent- No. 433,152, dated July29,1890.

Application filed January 20,

To all whom it may concern.-

Be it known that I, MAX SCHROEDER, of Neumilhl-llamborn, Empire ofGermany, a citizen of Germany, have invented certain new and usefulImprovements in Processes of Extracting Fats and Oils, (which werepatented to me in Germany by Letters Patent No. 50,360, dated June 13,1889, and in France by Letters Patent No. 200,313, dated August 21,1889,) of which the following is a specification.

This invention relates to an improved process of extracting fats andoils from substances containing the same by means of compressed liquidsulphurous acid, the invention being based on the recently-discoveredfact that liquid sulphurous acid is a good solvent for fats and oils.This acid does not mix, however, in all proportions with the fats andoils to a homogeneous liquid; but the relative proportions have to besuch that the extraction of the fatty substances may be accomplishedafter a certain time in the same manner as with benzine orcarbon-sulphide. Aslong as a surplus quantity of oil is present, themixture between the liquid sulphurous acid and the oil becomes a perfectone; but this mixing is not so perfect when the sulphurous acid is present in abundance, as in that case, especially with low temperature (of30 centi grade and below,) according to the quality of the oil, twosuperposed columns are formed, of which the upper lighter one containsmore of theoil,besides sulphurous acid, while the lower heavier columncontains sulphurous acid which has but little oil in solution. Vith anincrease of temperature, however, the perfect mixing It appears, thus,that the liquid sulphurous acid is not as perfect a' medium fordissolving fats and oils as other known extracting media 3 but it has,on the other hand, advantages which outweigh this small andhardly-noticeable disadvantage.

An important advantage of the use of sulphurous acid as a solvent isthat there is no danger of fire, which is the case with hydrocarbonsolvents. Another advantage is that the liquid sulphurous acid, owing toits low boiling temperature, can be removed more easily from the fat oroil, as well as from the 1890. Serial No. 337,522. (Specimens)Patentedin Germany June 13, 1889, No. 50,360, and in France August 21,1839,11! 200,313.

materials from which the fat is extracted. The process of extraction bymeans of liquid sulphurous acid does not diifer essentially from othermethods of extraction. It is to be observed, however, that theextraction, corresponding to the nature of the liquid sulphurous acid,has to take place underahigher pressure than with other customarysolvents. The apparatus used for this purpose has to beconstructed,therefore, much stronger, as a pressure of from five to sixatmospheres has to be provided for.

The extraction can take place in a cylindrical vessel on thecounter-current principle or in asimpler man nerbypassing asmallquantityof solvent by means of distillation and percolation overtheoil-containing substances. For the latter purpose it is preferable touse an upright iron cylinder or receiver, which is provided with thenecessary openings for the filling and discharging of the materials, andwith a grate or screen near the bottom, on which the same are supported,the openings to be provided with tightly-closing covers. Below the grateor screen is located a steam supply pipe, while at the upper part asupply-pipe for the introduction of the liquid sulphurous acid and atthe bottom a discharge-pipe for the oil is arranged. The apparatusrequires in, addition to these parts, a safety-valve with anoutlet-pipe, a pressuregage, a thermometer, and a pipe connected to thetop of the receiver, which pipe may be closed by a stopcock, and whichis connected with a condensing-coil th'at is arranged above the cylinderand provided with a valve at the upper end. Owing to the low boilingtemperature of the liquid sulphurous acid, it is necessary to arrange avalve by which the cooling-coil can be shut off during the extractionprocess.

The accompanying drawing shows one form of extraction apparatus adaptedto be used in my process of extracting oilsand fats by means of liquidsulphurous acid under pressure.

A in the drawing represents the receiver, which is filled with thematerial to be extracted, such as crushed or comminuted cotton-seed,palm-seed, cocoanuts, &c.; B, the

reservoir for the liquid sulphurous acid; 0, the vessel for separatingthe latter from the oil extracted by means of steam-heat, and D, acondensing-coil for the sulpl'iurous-acid vapors. The coil D isconnected bya valved pipe e with the receiver and by avalved pipe f withthe reservoir for the acid. During the extraction the pipe e is open andthe pipe f closed,while when the extraction is completed pipe 6 isclosed and pipef opened, so that the condensed acid can return to thereservoir 13. The acid required for extraction is charged through thepipe a from the reservoir B'into the receiver A. The oil dissolved bythe acid is conducted from the receiver A through the pipe I) to thevessel C, which latter can be heated by the steam-coil g h. The Vaporsof the acid pass from the vessel 0 through pipe d to the condensing-coilD,which latter is cooled by a continuous fiow of water. The oil fromwhich the acid has been separated is drawn 01f at the bottom of thevessel 0 by the pipe (1. The acid still remaining in the materialextracted is driven off by means of steam, which is admitted" throughpipe 2', the outletpipe is for the mixed steam and vapors being arrangedat the upper part of the receiver A. The sulphurousacid vapors areseparated in a cooling apparatus from the steam and re turned afterdrying by means of compressors to the reservoir B.

The apparatus is constructed of iron and lined with lead. Thepipes aremade of copper, and all parts tested for a pressure of twelveatmospheres.

The operation is as follows: After the receiver is filled with thematerial to be extracted and all the openings closed, the requiredquantity of sulphurous acid isintroduced in liquid state under pressureinto the receiver, while the air containing some gaseous sulphurous acidis allowed to escape through valve 61 at the upper part of thecooling-coil, so as to be removed from the apparatus. In practice aproportion of seventy-five parts of liquid sulphurous acid to onehundred parts of the material containingabout fifty per cent. of oil hasgivengood results. The liquid sulphurous acid is then gradually heatedby the steam-coil in the vessel 0 to a temperature of from 30 to 40centigrade, whereby a pressure pf from five to six atmospheres isdeveloped in the apparatus. The sulphurous-acid gases percolate throughthe material to be extracted, and are partly condensed in the same andreturned mixed with oil to the collecting-vessel 0. As soon as thematerial to be extracted has assumed the temperature of the acid thecondensation and return of the liquid sulphurous acid is acconr plishedby means of the cooling-coil. As soon as the extraction is completed,which, according to the quantity and density of the material to beextracted, takes place in from a few hours to a few days, the mixedsulphurous acid and oil which is collected at the vessel 0 of theapparatus is subjected to distillation,

either directly in said vessel or in a separate boiler. During thedistilling process the cooling-coil is connected with a closed vessel,which serves as a reservoir for the liquid sulphurous acid.

For removing the sulphurous-aci l gases from the interior of theapparatus it'is necessary to use an exhauster, by which the gases aredrawn off and returned into the collectingreservoir. The small quantityof sulphurous acid which still remains in the material from which thefatty oil is extracted is removed from the same by means of steam or hotair, which is forced through the same. In case steam is used for thispurpose it is necessary to cover the interior of the apparatus withlead, so as to prevent the destructive influences of the dilutesulphurous acid which is formed thereby on the walls of the same.

Having thus described my invention, I claim as new and desire to PatentI 1. The process herein described of extracting oils and fats frommaterials containing the same, which consists in subjecting the same tothe elutriating action of sulphurous acid and then separating said acidfrom the oil or fat by distillation and condensation, substantially asset forth.

2. The process herein described of extracting oils and fats frommaterials containing the same, which consists in subjecting saidmaterials to the elutriating action of sulphurous acid under pressure,separating the acid from the oil or fat by distillation andcondensation, and finally removing the acid remaining in the materialsextracted by steam or hot air, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in pres ence of two subscribing witnesses.

MAX SCHROEDER.

Witnesses:

L. A. EDWARDS, W. HAUPT.

secure by Letters

